Several methods and devices for user identification based on biometrics are available to filter or to authorize users accessing value added services. For example:
EP1593964A1 discloses a biological sensor device including a sensor-mounting element worn on a portion from a front surface to a side surface of an upper part of a face of a user; and a plurality of biological sensors that is installed on the sensor-mounting element and that measures different types of biological conditions of the user. In the biological sensor device, a plurality of biological sensors for measuring different types of biological conditions, such as an electromyography sensor and a temperature sensor, a temperature sensor and a vibration sensor, or a vibration sensor and a blood flow sensor is installed on the sensor-mounting element. Thus, by analyzing the plurality of different types of biological conditions acquired by the plurality of biological sensors, the psychological state of the user who views or listens to content can be estimated and determined.
US2006/115130A1, disclose an eyewear display system, which provides effective means for biometrically authenticating pre-enrolled users thereto. The eyewear display system integrates a biometric sensor that can determine the identity of the wearer who seeks to access image and/or audio data that is secured, sensitive, or otherwise subject to security controls, restrictions, and limitations on usage and viewing. The system may include a biometric authentication module with an embedded iris scanner subsystem or may implement fingerprint scanning. The system is also able to detect the presence or absence of a user. More specifically, the eyewear display system can sense the appearance of a prospective user, so that user can be prompted by the system for authentication. Conversely, when the eyeglasses are removed from the user's head, the system can detect this event and terminate the transmission of sensitive images from the signal feed source to the display. A proximity sensor can be implemented as a mechanical switch coupled to the body of the eyeglasses to sense the motion of a spring-hinged temple (ear-piece) when the frame is spread to place it on the user's head. This switch would have an operating position and a non-operating position, wherein the member is in the non-operating position in the absence of the user from the eyeglass frame and the switch is moved to the operating position when the user has placed the eyeglass frame on his or her head. Alternatively, the proximity detector may be electronic and may include a semiconductor device. The presence sensing mechanism may be optical, such as an infrared (IR) reflection detector, or acoustic, such as a high-frequency sonic range detector. Another example of a presence detection mechanism is the detection of the presence or absence of an iris image obtained from a silicon photo-detector array.
US2005/238194A1 discloses a human-machine interface which can detect when a user's ear is pulled back to initiate a plurality of procedures. Such procedures include turning on a TV using a laser attached to the user, starting an additional procedure by speaking a command, communicating with other users in environments which have high ambient noise, and interacting with the internet. Head position sensors are used to detect the position of the head of a user and to either initiate a procedure if a characteristic of the head position or positions meets a certain criteria, or to pass the head position information to another device. A transmitting apparatus having a sensor for detecting an ear pull of a user and a laser worn by the user. An electronic module is coupled to both the ear pull sensor and the laser and generates a laser beam upon detection of the ear pull. The ear movement sensors may be based on capacitance changes between plates located on the body of the user and on the frame of the eyeglasses. Also, the ear movement can be detected by detecting a change in the magnitude of an RF field or a magnetic field using a detector in an electronic module located in an ear clip. Also the resistance of the user's skin proximate to the ear would change sufficiently to detect an ear movement. A strain gauge together with an electronic module detects the change of the strain in the temple piece when the ear is pulled back. When the ear movement is detected, the electronic module connected to a laser generator by wires hidden behind or inside the temple piece of the glasses, causes the laser to send the predetermined code which activates a sensor to turn on or turn off the TV set. The transmitting apparatus for a user which has a plurality of sensors for detecting a head position of the user, a RF transmitter and an electronic module coupled to the plurality of sensors and to the RF transmitter. The electronic module generates an encoded RF signal containing information about the head position of the user.